1 /* 2 * Extensible Firmware Interface 3 * 4 * Based on Extensible Firmware Interface Specification version 1.0 5 * 6 * Copyright (C) 1999 VA Linux Systems 7 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com> 8 * Copyright (C) 1999-2002 Hewlett-Packard Co. 9 * David Mosberger-Tang <davidm@hpl.hp.com> 10 * Stephane Eranian <eranian@hpl.hp.com> 11 * 12 * All EFI Runtime Services are not implemented yet as EFI only 13 * supports physical mode addressing on SoftSDV. This is to be fixed 14 * in a future version. --drummond 1999-07-20 15 * 16 * Implemented EFI runtime services and virtual mode calls. --davidm 17 * 18 * Goutham Rao: <goutham.rao@intel.com> 19 * Skip non-WB memory and ignore empty memory ranges. 20 */ 21 22 #include <linux/kernel.h> 23 #include <linux/types.h> 24 #include <linux/ioport.h> 25 #include <linux/efi.h> 26 27 #include <asm/io.h> 28 #include <asm/desc.h> 29 #include <asm/page.h> 30 #include <asm/pgtable.h> 31 #include <asm/tlbflush.h> 32 #include <asm/efi.h> 33 34 /* 35 * To make EFI call EFI runtime service in physical addressing mode we need 36 * prolog/epilog before/after the invocation to claim the EFI runtime service 37 * handler exclusively and to duplicate a memory mapping in low memory space, 38 * say 0 - 3G. 39 */ 40 41 int __init efi_alloc_page_tables(void) 42 { 43 return 0; 44 } 45 46 void efi_sync_low_kernel_mappings(void) {} 47 void __init efi_dump_pagetable(void) {} 48 int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) 49 { 50 return 0; 51 } 52 53 void __init efi_map_region(efi_memory_desc_t *md) 54 { 55 old_map_region(md); 56 } 57 58 void __init efi_map_region_fixed(efi_memory_desc_t *md) {} 59 void __init parse_efi_setup(u64 phys_addr, u32 data_len) {} 60 61 pgd_t * __init efi_call_phys_prolog(void) 62 { 63 struct desc_ptr gdt_descr; 64 pgd_t *save_pgd; 65 66 /* Current pgd is swapper_pg_dir, we'll restore it later: */ 67 save_pgd = swapper_pg_dir; 68 load_cr3(initial_page_table); 69 __flush_tlb_all(); 70 71 gdt_descr.address = __pa(get_cpu_gdt_table(0)); 72 gdt_descr.size = GDT_SIZE - 1; 73 load_gdt(&gdt_descr); 74 75 return save_pgd; 76 } 77 78 void __init efi_call_phys_epilog(pgd_t *save_pgd) 79 { 80 struct desc_ptr gdt_descr; 81 82 gdt_descr.address = (unsigned long)get_cpu_gdt_table(0); 83 gdt_descr.size = GDT_SIZE - 1; 84 load_gdt(&gdt_descr); 85 86 load_cr3(save_pgd); 87 __flush_tlb_all(); 88 } 89 90 void __init efi_runtime_update_mappings(void) 91 { 92 if (__supported_pte_mask & _PAGE_NX) 93 runtime_code_page_mkexec(); 94 } 95